Flexible border rod

ABSTRACT

A mattress having a border rod assembly and at least one central spring core. The border rod assembly having individual border rods and corner pieces fitting together to create a contiguous border around and attached to the central spring core. A resilient, polymer material is used for at least one of the individual border rods. Border rod assemblies serve a dual purpose in mattress construction, acting both as a frame to which fabrics and foams may be attached and as a support structure for the central spring core, eliminating unsightly sagging and bowing at the mattress edge. Using resilient materials for the border rods allows the mattress to be used interchangeably with adjustable and non-adjustable foundations, while retaining the rigidity and desirable structural aspects of standard steel border rod mattresses.

FIELD OF THE INVENTION

[0001] This invention relates to mattresses, and more particularly, to mattresses for use interchangeably with adjustable or non-adjustable foundations.

BACKGROUND OF THE INVENTION

[0002] The ability to move a bed from a horizontal sleeping position to an upright sitting position makes adjustable beds a practical necessity a hospital environment. Though not rising to the level of necessity, the same adjustable features make the same beds attractive to the home consumer, permitting homeowners to position their beds for other activities such as reading, watching television, or dining.

[0003] The typical adjustable bed is comprised of an adjustable frame and a mattress specially designed for adjustable use. Standard flat mattresses perform poorly in adjustable applications due to rigid internal structures. Steel border wires, common to traditional mattress constructions, provide a framework for the mattress upholstery and add stiffness to the inner spring assembly. However, when used with an adjustable frame, the border wires prevent traditional mattresses from naturally conforming to the adjusted frame. Conformity between the mattress and frame may be forced, but at the risk of causing permanent deformation the border wires, leaving the consumer with a mattress that may never fully return to the horizontal sleeping position.

[0004] To deal with the inflexibility of traditional flat mattresses and the demand of adjustable bedding products, bedding manufacturers have generated numerous specialty mattress designs for use with adjustable frames. These specialty designs range from segmented mattresses, which use sections of traditional mattress constructions connected by foam or cloth joints, to foam mattresses, abandoning traditional designs altogether. Unfortunately, with deviations from traditional mattress designs come undesirable characteristics in the final product, such as reduced comfort and durability for the bedding product. The foam joints in the segmented mattress design, for example, typically have a shorter useable lives and are noticeably less comfortable in the horizontal sleeping position than their traditional counterparts.

[0005] Consumer concerns aside, a single mattress construction useable with both adjustable or non-adjustable foundations generates significant efficiency savings for a manufacturer of mattresses. Multiple mattress designs translates into multiplied costs in the form of tooling, employees, workspace, and storage, not to mention added marketing requirements. A mattress that can be used with either adjustable or non-adjustable foundations would merge two currently distinct consumer groups for the mattress manufacturer, reducing operating costs or even opening up new markets formerly inaccessible due to cost concerns.

[0006] Thus, there is a need in the art for a one-design mattress that may be used with an adjustable or non-adjustable foundation without compromising the comfort or structural integrity of a standard steel border rod mattress assembly.

SUMMARY OF THE INVENTION

[0007] The invention includes mattress having a border rod assembly and at least one central spring core. The border rod assembly, comprising border rods and corner pieces with at least one border rod being a resilient polymer material, forms a contiguous border around and attached to the central spring core. Border rod assemblies serve a dual purpose in mattress construction, acting both as a rigid frame to which fabrics and foams may be secured, and as a stiffening structure surrounding the central spring core preventing unsightly sagging and bowing of the mattress edge.

[0008] However, the benefits of border rod rigidity are accompanied by several drawbacks. For instance, one common malady of returned mattresses is permanent deformation to border rods due to folding of the mattress during delivery into space-restricted locations. Similarly, border rod rigidity prevents traditional mattresses from being used with adjustable bed foundations.

[0009] Using resilient polymers for border rods permits the mattress to be used interchangeably with adjustable and non-adjustable applications, while retaining the rigidity and other desirable structural characteristics that accompany traditional steel border rod constructions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The foregoing and other objects and advantages of the invention will be appreciated more fully from the following description thereof, with reference to the accompanying drawings wherein;

[0011]FIG. 1 is a cutaway view of one mattress according to the invention.

[0012]FIG. 2 is an exploded view of one embodiment of a border rod assembly according to the invention.

[0013]FIG. 3 depicts an alternative embodiment of a border rod assembly according to the invention.

[0014]FIG. 4 illustrates one mattress according to the invention placed on a conventional adjustable frame in an adjusted position.

[0015]FIG. 5 illustrates one mattress according to the invention placed on a conventional adjustable frame in a horizontal sleeping position.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0016]FIG. 1 illustrates a cutaway view of a mattress 10 according to one embodiment of the invention. The cutaway portion reveals the central spring core 18, which may be comprised of pocketed coils, open coil springs, or other conventional inner spring constructions. Also visible is the border rod assembly 12, which encircles the central coil spring 18, and is coplanar with the upper mattress surface 16. The border rod assembly 12 may, in other embodiments, encircle the central spring core 16 at any plane located along the thickness 22 of the mattress, or immediately above (below) the upper mattress surface 16 (the lower mattress surface 14). While the depicted embodiment shows only a single border rod assembly 12, alternative embodiments may use multiple border rod assemblies 12 located at any of the locations described herein. The border rod assembly 12 is attached to the central spring core 18 with hog rings 20. Other embodiments of the invention may use plastic clips, locking cable ties, wire twists, lacing, or other means of attachment that will be apparent to one of skill in the art.

[0017] Moving to the next drawing, FIG. 2. shows an exploded view of one embodiment of the border rod assembly 12. In the depicted embodiment, the border rod assembly 12 comprises individual border rods 26 and individual corner pieces 24 terminally connecting at least two border rods 26 forming a contiguous rectangular perimeter. In an alternate embodiment, the border rod assembly 12 may comprise only border rods 26, without corner pieces 24. The border rods 26 may be a single, continuous rod, or multiple short rods 38 terminally connected to achieve a desired length as depicted in the blowup view 36 of FIG. 2. Though FIG. 2 only shows a single border rod 26 per edge, alternative embodiments may use multiple parallel border rods 26 to achieve the desired structural characteristics.

[0018] The border rods 26 shown in FIG. 2 are solid and cylindrical in shape. Cylindrical border rods, however, are not required by the invention, and other embodiments may use square, hexagonal, or other common cross-sectional shapes. Furthermore, solid border rods are not required by the invention, and hollow border rods may be used.

[0019] The border rods 26 depicted in the embodiment of FIG. 2 are made of a resilient polymer material such as a plastic, epoxy, or other polymers, however any suitable flexible material may be employed. For added durability, resilient polymer material may be reinforced with fiberglass or other fiber strands. The border rod assembly 12 according to the invention, however, does not require that each border rod 26 be made of the resilient polymer material. As would be apparent to one of skill in the art, the border rods 26 along the short mattress dimension 32 may not require the additional flexibility offered by the resilient polymer material to function properly with an adjustable frame. Therefore, in one embodiment, the border rod 26 along the short mattress dimension 32 may be made of a material other than the resilient polymer, such as steel or other traditional materials known to one of skill in the art.

[0020]FIG. 2 shows one embodiment of the invention in which a unitary resilient polymer border rod 30 flexes in response to a downward force 28. In another embodiment, the border rods 26 of FIG. 2 may be comprised of terminally connected lengths of short rods 38, as shown in the blowup view 36. Terminal connections may be achieved through a ferrule-type connector 40 as depicted in blowup view 36, or by any other connection means known to one of skill in the art.

[0021] As would be apparent to one of skill in the art, some applications may require flexibility only in certain areas of the border rods 26, for example, as shown in FIGS. 4 and 5, a length of the border rod 26 coinciding with a pivot point 50 in an underlying adjustable frame 48. In one embodiment of the ferrule-connected border rods of blowup view 36, resilient polymer short rods 38 may be connected to short rods 38 made of an alternate material to achieve a desired flex profile along the border rod 26. Terminally connecting short rods 38 of differing materials would permit flexibility profiles along the length of the border rods 26 specifically designed to meet the requirements of an adjustable frame as shown in FIG. 4. Resilient polymer border rods 26 or short rods 38 may be employed in any one or all of the sides of the border rod assembly 12, as long as at least one of the border rods 26 is made of the resilient polymer material.

[0022] The flexibility profile of the mattress 10 may also be shaped by varying the diameter along the length of the border rod 26 or short rod 38. Blowup 42 shows one embodiment of the invention using different diameters to focus flexibility in certain areas of the border rod assembly 12. In blowup 42, two large diameter sections 44 are connected by a small diameter section 46. The small diameter section 46 is made of the resilient polymer material. In the embodiment shown in blowup 42, the large diameter sections 44 and the small diameter section 46 comprise a unitary length of the resilient polymer material.

[0023] The section depicted in blowup 42 may be a section of a border rod 26 or of a short rod 38 terminally connected to other short rods 38. The transition between the large diameter section 44 and the small diameter section 46 may be a conical chamfer, as shown in blowup 42. In other embodiments, the transition between diameters may be a square shoulder, having no chamfer at all, or a continually decreasing diameter instead of a finite transition zone. In another embodiment of the mattress, the large diameter sections 44 may be comprised of a material other than the resilient polymer material, with the small diameter section 46 made of the resilient polymer material. Where the large diameter sections 44 and the small diameter sections 46 are of a different material, or even where they are the same material but not part of a unitary border rod 26, the sections may be connected in a manner similar to the connections described herein between the short rods 38 depicted in blowup 36.

[0024] The corner pieces 24 of FIG. 2 terminally connect at least two border rods 26. As depicted, the corner pieces 24 are flexible tubing with an inner diameter sized to grippingly engage the outer surface of the border rods 26. Being flexible tubing, the corner pieces 24 may permit variations in the angle between the connected border rods 26. Other embodiments may include corner pieces 24 made of molded polymer material with integral sockets for accommodating a terminal portion of the border rods 26. In contrast with the flexible tubing corner pieces 24 depicted in the figure, molded polymer corner pieces maintain a fixed-angle relationship between the border rods 26 connected. The connection between the corner piece 24 and the border rod 26 may be maintained through slip joint, glue, weld, or other method known to one of skill in the art.

[0025]FIG. 3 shows an alternate embodiment of the border rod assembly 12. Rather than being comprised of individual border rods and corner pieces as depicted in FIG. 2, the border rods 26 and corner pieces 24 are integrally molded into a unitary, continuous rectangular perimeter. As a result, the border rod assembly 12 may not be disassembled as shown by the exploded view of FIG. 3. Additionally, being a singular unit, the molded border rod assembly of FIG. 3 is entirely made of the resilient polymer material.

[0026]FIGS. 4 and 5 show one mattress 10 according to the invention used with an adjustable foundation 30. FIG. 4 depicts one mattress 10 according to the invention on the adjustable foundation 48 in an adjusted position. In contrast to mattresses following traditional construction methods, the mattress 10 conforms to the adjustable foundation 36 under its own weight without requiring additional assistance. In FIG. 5, when the adjustable foundation 48 is returned to the horizontal sleeping position, the mattress again conforms to the surface under its own weight. Again in contrast with traditional mattresses, the mattress 10 returns to its natural position without remnant distortions in the border rods resulting from the adjusted positioning depicted in FIG. 4. The advantages gained from implementing resilient polymer material in the border rod assembly 12 are not limited interchangeable use with adjustable foundations 48. For example, challenges of product shipment and delivery may also be alleviated through added mattress flexibility. One common cause of returned mattresses is permanent deformation in steel border rods resulting from contortions endured during shipment, or delivery into confined areas, a problem that may be avoided through the use of resilient polymer materials in a border rod assembly. 

What is claimed is:
 1. A mattress having a border rod assembly, comprising a plurality of border rods, at least one being made of a resilient polymer material, a plurality of corner pieces connecting at least two of the plurality of border rods, and at least one central spring core being coupled to at least one of the plurality of border rods.
 2. The mattress of claim 1, wherein the border rod assembly forms a contiguous rectangular perimeter with a longer dimension and a shorter dimension, wherein at least one of the border rods comprising the longer dimension of the rectangular perimeter is comprised of the resilient polymer material.
 3. The mattress of claim 1, the resilient polymer material being plastic.
 4. The mattress of claim 1, the resilient polymer material being epoxy.
 5. The mattress of claim 1, the resilient polymer material being reinforced with fiber strands.
 6. The mattress of claim 1, at least one of the resilient polymer border rods being hollow.
 7. The mattress of claim 1, at least one of the resilient polymer border rods being solid.
 8. The mattress of claim 1, at least one of the plurality of corner pieces being rigid, retaining a fixed-angle relationship between at least two of the plurality of border rods connected by the corner piece.
 9. The mattress of claim 1, at least one of the plurality of corner pieces being flexible and permitting variation in the angle between at least two of the plurality of border rods connected by the corner piece.
 10. The mattress of claim 1, at least one of the plurality of corner pieces being molded polymer material and having at least two sockets, each socket being sufficiently large to receive a terminal length of the border rod.
 11. The mattress of claim 1, at least one of the plurality of corner pieces being flexible tubing, the inner diameter of the tubing being sufficiently large to accommodate a terminal length of one of the plurality of border rods concentrically located within the inner diameter of the tubing.
 12. The mattress of claim 1, wherein the plurality of border rods and corner pieces are integrally molded into the border rod assembly.
 13. The mattress of claim 1 being unoccupied, the border rod assembly having sufficient pliability to maintain conformity between a surface of the mattress and an adjustable foundation supporting the mattress while the adjustable foundation is in an adjusted position.
 14. A mattress having a border rod assembly, comprising a plurality of border rods, at least one being made of a resilient polymer material, and at least one central spring core being coupled to at least one of the plurality of border rods.
 15. The mattress of claim 14, the resilient polymer material being plastic.
 16. The mattress of claim 14, the resilient polymer material being epoxy.
 17. The mattress of claim 14, the resilient polymer material being reinforced with fiber strands.
 18. The mattress of claim 14, at least one of the resilient polymer border rods being hollow.
 19. The mattress of claim 14, at least one of the resilient polymer border rods being solid.
 20. A mattress for an adjustable bedding system, comprising at least one central spring core, a flexible border rod assembly, having a plurality of resilient, fiberglass-reinforced, polymer border rods, a plurality of corner pieces terminally connecting one of the plurality of border rods to another one of the plurality of border rods forming a contiguous rectangular perimeter, the plurality of corner pieces being flexible poly tubing.
 21. The mattress assembly of claim 20, the flexible border rod assembly being attached to the perimeter of the central spring core and encircling the central spring core.
 22. The mattress assembly of claim 20, the plurality of border rods being solid and cylindrical.
 23. The mattress assembly of claim 20, the corner pieces having an inner diameter sufficiently large to accommodate a terminal length of one of the plurality of border rods concentrically located within the inner diameter of the tubing.
 24. A method of manufacturing a mattress with a border rod assembly, comprising assembling a border rod assembly by connecting a plurality of border rods with a plurality of corner pieces to form a contiguous rectangular perimeter, at least one of the plurality of border rods being made of a resilient polymer material, and attaching at least one of the plurality of border rods to at least one central spring core.
 25. The method of claim 24, wherein the connection between one of the plurality of flexible border rods and one of the plurality of corner pieces is a slip joint.
 26. The method of claim 24, wherein the flexible border rods are attached to the central spring core through hog rings.
 27. The method of claim 24, wherein the flexible border rods are attached to the central spring core through clips. 